Our sustainable city tour takes us from Freiburg im Breisgau to Issy-les-Moulineaux, a city which based its energy strategy on smart grids with a view to create IssyGrid®, the first “smart neighbourhood grid” in France. Here is an account of this innovative challenge.

Project implementation and energy optimization goal

Various players pooled their complementary expertise to conceive the “city of the future”. As of today, ten companies are involved in the project: Alstom, Bouygues Immobilier, Bouygues Telecom, EDF, ERDF, ETDE, Microsoft, Schneider Electric, Steria et Total, together with local authorities and several greentech start-ups (such as Ijenko and Linky).

IssyGrid® was launched in 2011 and hopes to take up a threefold challenge: increasing worldwide energy demand, anticipated higher energy costs and environmental concerns. Furthermore, it takes into account measures imposed by European and national regulations, such as the “energy package” (see our introduction to the “sustainable cities” series of articles).

Energy optimization is a three-pronged approach: sustainable and smart consumption (use less and at the right time), integration of sustainable energy generation at the local level and a better management of energy and energy use (distribution and grids).

Fitting homes with energy efficiency devices

The first monitoring phase was launched in the Seine Ouest neighbourhood in early 2012 by installing innovative energy optimization devices. A dozen test-homes were fitted with consumption-specific monitoring devices (heating, lighting, hot water, etc.) so as to assess the consumption related to each piece of equipment. Smart thermostats were also installed in order to enable users to remotely monitor their home’s temperature. Finally, temperature and humidity sensors now allow for indoor environmental quality assessment. In addition, the Linky smart metre was used to complement this scheme. All of this equipment generates data which is instantly fed to the neighbourhood’s energy information centre via the internet. This experiment was extended to around thirty homes in 2012.

Smart and efficient buildings

The headquarters of Bouygues Immobilier, located in the new Galeo Building, served as a test building. It relies on renewable energy sources (solar panels) and is equipped with an interface allowing for energy consumption measurement and control, which manages energy generation (via the local grid), distribution and consumption. In the course of 2012, this scheme was extended to four other office buildings in the area.

A networked system allowing for local energy optimization

The eco-neighbourhood’s “information, expertise and counselling network centre” gathers data on power consumption from homes and office buildings. The centre processes this data and offers improvement suggestions to all of the network’s players, households and businesses alike. Renewable energy generation and storage are also networked.

In order to mitigate consumption peaks, engineers even conceived a system of communicating vessels between office buildings, generating excess power in the weekends, and homes, which need more power precisely at that time.

Just recently, the monitoring scheme started including “smart public lighting” which adapts to road traffic and natural light in real time. Besides, electric car charging stations are now available.

The interconnection of energy equipment within the smart grid enables to fine-tune consumption and to control energy demand, which are key aspects of energy efficiency.

Development of the digital eco-neighbourhood Fort d’Issy in 2013

The current scheme concerns nearly 10,000 people in an area of 160,000 m² and will be extended to the 1,600 homes of the Fort d’Issy residential neighbourhood. The Urban Era sustainable neighbourhood (project launched by Bouygues Immobilier) will strive to create an “urban ecosystem”, a smart digital eco-neighbourhood. Smart buildings will be interconnected via a smart grid and fitted with efficient energy systems. For instance, digital displays will be installed at the entrance of each home to control consumption and adjust light and heat. Equipment will be mostly power by geothermal energy.